For British Science Week 2019, we are looking back at how Great Britain has shaped different scientific fields through its research and innovation. First, we are delving into genetics and molecular biology – from Darwin’s legacy, to the structure of DNA and now modern molecular techniques.
The theory of evolution by natural selection is one of the most famous scientific theories in biology to come from Britain. Before Charles Darwin famously published this theory, several classical philosophers considered how some traits may have occurred and survived, including works where Aristotle pondered the shape of teeth.
These ideas were forgotten until the 18th century, when they were re-introduced by philosophers and scientists including Darwin’s own grandfather, Erasmus Darwin.
Darwin used birds, particularly pigeons and finches to demonstrate his theories. Image: Pixabay
In 1859, Darwin first set out his theory of evolution by natural selection to explain adaptation and speciation. He was inspired by observations made on his second voyage of HM Beagle, along with the work of political economist Thomas Robert Malthus on population.
Darwin coined the term ‘natural selection’, thinking of it as like the artificial selection imposed by farmers and breeders. After publishing a series of papers with Alfred Russel Wallace, followed by On the Origin of Species, the concept of evolution was widely accepted.
Although many initially contested the idea of natural selection, Darwin was ahead of his time, and further evidence was yet to come in the form of genetics.
Gregor Mendel first discovered genetics whilst working on peas and inheritance in the late 19th century. The unraveling of the molecular processes that were involved in this inheritance, however, allowed scientists to study inheritance and genetics in a high level of detail, ultimately advancing the field dramatically.
A major discovery in the history of genetics was the determination of the structure of deoxyribose nucleic acid (DNA).
DNA was first isolated by Swiss scientists, and it’s general structure – four bases, a sugar and a phosphate chain – was elucidated by researchers from the United States. It was a British team that managed to make the leap to the three-dimensional (3D)structure of DNA.
Using x-ray diffraction techniques, Rosalind Franklin, a British chemist, discovered that the bases of DNA were paired. This lead to the first accurate model of DNA’s molecular structure by James Watson and Francis Crick. The work was initially published in Nature in 1953, and would later win them a Nobel Prize.
The age of genetic wonder. Source: TED
By understanding the structure of DNA, further advances in the field were made. This has lead to a wide range of innovations, from Crispr/CAS9 gene editing to targeted gene therapies. The British-born science has been utilised by British pharmaceutical companies – pharma-giants GlaxoSmithKline (GSK) and AstraZeneca use this science today in driving new innovations.
2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today, on International Women’s Day, we look at the two elements radium and polonium and the part Marie Curie that played in their discovery.
Who is Marie Curie?
Marie Sklodowska and her future husband Pierre Curie.
Marie Sklodowska-Curie was born in 1867 in Poland. As a young woman she had a strong preference for science and mathematics, so in 1891 she moved to Paris, France, and began her studies in physics, chemistry and mathematics at the University of Paris.
After gaining a degree in physics, Curie began working on her second degree whilst working in an industrial laboratory. As her scientific career progressed, she met her future husband, Pierre Curie, whilst looking for larger laboratory space. The two bonded over their love of science, and went on to marry, have two children and discover two elements together.
After finishing her thesis on ‘Studies in radioactivity’, Curie became the first woman to win a Nobel Prize, the first and only woman to win twice, and the only person to win in two different sciences.
Curie, along with husband Pierre and collaborator Henri Becquerel, won the 1903 Nobel prize in Physics for their radioactivity studies, and the 1911 Nobel prize in Chemistry for the isolation and study of elements radium and polonium.
Curie won the Nobel prize twice in two different subjects. Image: Pixabay
As of 2018, Curie is one of only three women to have won the Nobel Prize in Physics and one of the five women to be awarded the Nobel Prize in Chemistry.
Polonium, like radium, is a rare and highly reactive metal with 33 isotopes, all of which are unstable. Polonium was named after Marie Curie’s home country of Poland and was discovered by Marie and Pierre Curie from uranium ore in 1898.
Polonium is not only radioactive but is highly toxic. It was the first element discovered by the Curies when they were investigating radioactivity. There are very few applications of polonium due to its toxicity, other than for educational or experimental purposes.
Radium is an alkaline earth metal which was discovered in the form of radium chloride by Marie and her husband Pierre in December 1898. They also extracted it from uranite (uranium ore), as they did with polonium. Later, in 1911, Marie Curie and André-Louis Debierne isolated the metal radium by electrolysing radium chloride.
The discovery of radium led to the development of modern cancer treatments, like radiotherapy.
Pure radium is a silvery-white metal, which has 33 known isotopes. All isotopes of radium are radioactive – some more than others. The common historical unit for radioactivity, the curie, is based on the radioactivity of Radium-226.
Famously, radium was historically used as self-luminescent paint on clock hands. Unfortunately, many of the workers that were responsible for handling the radium became ill – radium is treated by the body as calcium, where it is deposited in bones and causes damage because of its radioactivity. Safety laws were later introduced, followed by discontinuation of the use of radium paint in the 1960s.
Marie Curie: A life of sacrifice and achievement. Source: Biographics
Curie’s work was exceptional not only in its contributions to science, but in how women in science were perceived. She was an incredibly intelligent and hard-working woman who should be celebrated to this day.